 Solution

The MENA solar resource could provide a useful supplement, but geographical potential does not make imports logically essential to European decarbonisation. With an illustrative annual mean insolation $200\mathrm{W}{\mathrm{m}}^{-2}$, photovoltaic conversion $15\%$ and system factor $0.8$, mean delivered-at-plant power is $24\mathrm{W}{\mathrm{m}}^{-2}$. A collector area of $10^4\mathrm{k}{\mathrm{m}}^2$ would then give $240\mathrm{GW}$ mean or about $2100\mathrm{TWh}$ annually before export losses. This is a scale calculation with stipulated assumptions, not a land-availability survey.

Long transmission corridors, converter losses, night-time supply, storage, dust, cooling or cleaning water, financing and political dependence must also be included. Solar thermal storage can shift some output but does not remove every seasonal or geopolitical risk. Projects should benefit host populations and avoid treating nominal desert area as empty infrastructure-ready land.

Europe also has domestic wind power, solar power, hydroelectricity, potential nuclear generation, demand reduction and other mitigation options. A technically credible combination of those is a counterexample to the word “essential”. MENA imports could reduce costs or improve diversity within a broader low-carbon system; whether they are preferable requires a complete system comparison rather than solar resource density alone.